INTRODUCTION: Spinal metastasis is a growing problem in patients with cancer. Although the efficacy of spinal metastasis surgery for maintaining or improving quality of life by alleviating pain and preserving neurologic function has recently been reported, the spinal metastasis surgery could make the patients’ general condition even worse because not a few spinal metastasis patients have poor general condition. We have previously reported the preoperative laboratory data would help predict the early deterioration of general condition after spinal metastasis surgery. The aim of current study was to predict the risk of early mortality after spinal metastasis surgery with our scoring system using preoperative laboratory data and existence of major organ metastasis.
METHODS: We created a scoring system, using preoperative laboratory data and existence of metastasis of major organs based on our previous reports, as follows: we allocated two points to C-reactive protein (CRP) ≥ 4.17mg/L, and one point to lactate dehydrogenase (LDH) ≥ 257U/L, calcium adjusted for albumin level (Ca) ≥ 10.1mg/dL, serum albumin (Alb) ≤ 3.1g/dL, respectively. We also allocated 0.5 points if patients had brain or visceral metastasis. Every patient was scored 0 to 5.5 points. Seventy patients (41 males and 29 females, with average age of 62.5 years old) out of 123 patients with spinal metastasis surgery from November 2013 to August 2018, who had preoperative laboratory data of all four items mentioned above, were included. We investigated if the scoring system could predict the early mortality within 30 days, 60 days and 90 days after surgery, respectively. Cut off value was determined by receiver operating characteristic curve (ROC curve) using Youden index.
RESULTS: The overall patients had median survival time of 4.5 months and had significantly improved PS one month after surgery (preoperative and postoperative median PS were 3 and 2, respectively). The number of patients who died within 30 days, 60 days and 90 days after surgery were 4 (5.7%), 12 (17%), 22 (31%), respectively. Cut off value, sensitivity, specificity and the area under the curve of ROC curve of early mortality were as follows: 4.5 points, 100%, 94%, 0.977 in 30-day mortality, 2 points, 100%, 74%, 0.92 in 60-day mortality, 2 points, 91%, 85%, 0.936 in 90-day mortality, respectively.
DISCUSSION: The current study indicated that our scoring system with preoperative laboratory data and existence of major organ metastasis might be helpful to predict the risk of early mortality after spinal metastasis surgery. Further prospective studies are needed to verify the validity of our scoring system and create the optimal medical care system of spinal metastasis.